Photos of Aurora suspect smiling with gun shown at hearing

A picture of shooting suspect James Holmes is shown in courtroom sketch from a preliminary hearing in Centennial, Colo., on Wednesday.

The preliminary hearing in the Aurora massacre case closed Wednesday with an indelible image: suspect James Holmes smiling into the camera while gripping a semiautomatic handgun, just six hours before the rampage.

The photo recovered from Holmes’ cellphone was one of dozen pictures prosecutors offered as evidence before they told a judge that the former grad student “didn't care who he killed.”

The defense presented no witnesses at the hearing, and the judge will rule on Friday whether there is enough evidence to put Holmes on trial for the July 20 mass murder at a suburban Colorado multiplex.

The prosecution’s last witness was an Aurora police detective who cataloged the photos, meant to show that Holmes painstakingly planned the ambush that killed 12 and wounded 58 during a screening of “The Dark Knight Rises.’

There were four photos of the inside and outside of the Century 16 theater, two taken as early as June 29. More arresting was a series of creepy self-portraits taken the evening of July 19 – Holmes’ hair dyed a shocking red and his eyes darkened by black contacts.

The preliminary hearing for James Holmes, who is accused of killed 12 in the Aurora, Colo., theater massacre, ended Wednesday when Holmes' defense attorney chose to call no witnesses to testify about Holmes' mental state. The judge will issue a ruling by Friday as to whether or not a trial will begin, and there is already speculation that the case may end with a plea agreement. NBC's Mike Taibbi reports.

In one, he stuck out his tongue. In another, he held an explosive device and puckered his lips. A third showed him smiling, holding a semiautomatic pistol in front of the lens.

Other pictures showed what prosecutors say were the tools his destruction: an assault rifle with a scope, a pump-action shotgun, a gas mask, helmet and body armor, all laid out on his bed. A few photos showcased the booby-traps that he allegedly set to explode in his home after the shooting.

Prosecutors said the photos, along with testimony from a parade of law-enforcement officers, left no doubt that Holmes was the gunman or that he was hell-bent on maximum carnage in the “perfect venue.”

“He didn't care who he killed or how many he killed, because he wanted to kill all of them," prosecutor Karen Pearson said

Holmes’ lawyer, Daniel King, had the go-ahead to call two witnesses who would testify about his client’s mental state. But he decided not to put anyone on the stand, saying the hearing was not the right forum for a “truncated” defense.

Scott Robinson, a Denver lawyer who is not involved in the case but has attended the proceedings, said it would be unusual for the defense to call witnesses during the preliminary hearing and show its hand to the other side.

Holmes, who is expected to mount an insanity defense, will return to court Friday. If the judge decides the case is going to trial, he will be arraigned on more than 160 counts of murder, attempted murder and weapons possession.

Bill Robles / Reuters

A picture of Colorado shooting suspect James Holmes, recovered from his cellphone, is shown in courtroom sketch from Thursday's preliminary hearing.

Legal experts said it would be stunning if the judge did not find there was probable cause for the case to proceed.

“In 31 years, I can think of one case where a court did not find probable cause,” former Denver prosecutor Karen Steinhauser said.

She said that if Holmes pleads not guilty by reason of insanity, the judge will order mental health evaluations and a trial date will not be set right away.

It’s possible that the defense and prosecution could strike a plea deal, in which case this week’s hearing will have been the closest thing to a trial. Much of the evidence is still under wraps because of a court-imposed gag order.

The three-day hearing focused on accounts from officers who arrested Holmes outside the theater and tried to save the victims inside. The testimony was at times graphic and heart-breaking, leaving witnesses and spectators – many of them relatives of the killed and injured – in tears.

Throughout, Holmes was impassive, sitting nearly motionless in a jail-issue jumpsuit, the dyed crimson mop he sported in the pre-slaughter photos replaced by messy brown hair and a beard.